Add is_transforming_instant_article() conditional

class-instant-articles-post.php

@@ -595,6 +595,8 @@ public function to_instant_article() {
 		 */
 		do_action( 'instant_articles_before_transform_post', $this );
 
+		is_transforming_instant_article( true );
+
 		// Get time zone configured in WordPress. Default to UTC if no time zone configured.
 		$date_time_zone = get_option( 'timezone_string' ) ? new DateTimeZone( get_option( 'timezone_string' ) ) : new DateTimeZone( 'UTC' );
 
@@ -690,6 +692,8 @@ public function to_instant_article() {
 
 		$this->instant_article = apply_filters( 'instant_articles_transformed_element', $this->instant_article );
 
+		is_transforming_instant_article( false );
+
 		/**
 		 * Fires after the instant article is rendered.
 		 *

facebook-instant-articles.php

@@ -157,6 +157,21 @@ function instant_articles_feed() {
 
 	}
 
+	/**
+	 * Whether currently processing an instant article.
+	 *
+	 * @param bool Set the status
+	 * @return bool
+	 */
+	function is_transforming_instant_article( $set_status = null ) {
+		static $is_instant_article = false;
+
+		if ( isset( $set_status ) ) {
+			$is_instant_article = (bool) $set_status;
+		}
+
+		return $is_instant_article;
+	}
 
 	/**
 	 * Modify the main query for our feed.